The present invention relates to cable terminals in general and to caps and connectors which are fitted to the ends of cables to provide for temporary supply of electricity through such cables by connecting plugs and connectors with various receptacles and equipment for use of the electricity.
It is well known that cables are employed in numerous applications outside of building wire conduits and that such cables are frequently employed for the temporary supply of electricity to equipment. The temporary supply may be of a long term nature and the environment in which the cable and the connectors attached to the cables are used can be heavy industrial environments such as machine shops, mines and factories where cable is subject to becoming coated with dirt and machine chips and other contaminants of the enviroment which are normally and necessarily present in such use locations. Where certain types of environmental contaminants such as metallic dust and metallic grindings and chips and cuttings are present, it is possible for these substances to enter into the caps and connectors attached to cables to contaminate the interior of the caps and connectors. In some cases, if some solid or fluid material enters the cap or connector, it may form an electrical bridge between conducting metal portions within the cap or connector and may lead to a current leakage within the cap or connector which is undesirable or dangerous. Alternatively, metal contaminants in a connector forming such a bridge may lead to a shorting of the current carrying elements and to a destruction of the cap or connector. Accordingly care should be employed in use of caps and connectors in such environments and boots may be employed to keep moisture and contaminants from such connectors to reduce the problems mentioned above which may be associated with use of such caps and connectors.
It is also known that it is desirable in providing caps and connectors for attachment to electric cables that the cap and connector be capable of receiving a wide range of cable sizes. For example, an insulative cable which has three conductors of No. 12 AWG and which can carry 600 volts may have an outer insulation diameter of 5/8 inch. Such wire grip is taught in U.S. Pat. Nos. 3,984,168 and 3,989,340 assigned to the same assignee as the subject application. Other cables may have substantially smaller diameters.
While the occurrence of the contamination of the interior of such a cap and connector is related to the actual size of wire which is held within the wire clamp of the connector and the environment in which the connector is employed, it is nevertheless apparent that where it is feasible to do so, it is desirable to seal the entrance to the connector, and particularly to seal the region around the cable where smaller diameter cables are employed. Accordingly, if smaller diameter cables are to be employed in such a connector in an environment where high levels of contaminants are present, then it is desirable to have a closure for the connector or cap which is an alternative to an outer boot and which is nevertheless effective in keeping those contaminants from the interior of the cap or connector such effectiveness is related to closing a gap between the wide cable opening of the connector and the narrow cable extending through this opening in the absence of a coverall-type boot.